Tone-modifying attachment for pianos



2 Sheets-Sh t 1,

(No Model.)

J. 0. KING. TONE MODIFYING ATTACHMENT FOR PIANOS. No. 602,135. Patented Apr. 12, 1898.

Fig. l.

Wfrn E5725 2 S11eetsSheet 2.

(No Model.)

J. 0. KING. TONE MODIFYING ATTACHMENT FOR PIANOS. o. 602,135.

Patented Apr. 12, 1898.

"Fig. 2

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UNITED STATES PATENT OFFICE.

JOHN 0. KING, OF SAN FRANCISCO, CALIFORNIA.

TONE-MODIFYING ATTACHMENT FOR PIANOS.

SPECIFICATION forming part of Letters Patent No. 602,135, dated April 12, 1898.

Application filed April 27, 1897. Serial No. 684,160. (No model.)

To all whom it may concern.-

Be it known that I, JOHN 0. KING, a citizen of the United States, residing in the city and county of San Francisco and State of California, have invented certain new and useful Improvements in Tone-Modifying Attachments for Pianos, of which the following is a specification.

The class or description of attachments to which this invention relates is designed to modify or change the quality of tone of a piano, so as to produce imitations of the harp, mandolin, and other stringed instruments of similar quality of tone at the pleasure of the performer.

The object of the present improvements in these devices or attachments is to secure several advantages both in the construction and in the action or operation of the device, and particularly to obtain a uniform quality of tone throughout the entire scale of the piano and a delicacy of action that permits rapid passage and short notes to be effectively rendered in close imitation of the mandolin harp, or banjo. So far as I am aware the attachments to produce this quality of tone in a piano have heretofore been formed of a number of separate tongues or narrow strips of spring metal attached at one end to a carrying-bar and by the movement of said bar interposed between the strings and the hammers, so as to strike the strings under the impact of the hammer and to react by virtue of their resilience when the hammer is drawn back or away from them, each tongue carrying on its face next to the string a striking block or button standing away from the body of the tongue sufficiently to keep the tongue from making contact With the string. As an improvement upon such devices my said invention consists in a sheet or strip of thin elastic tissue or cloth, such as thin sheetrubber or a fabric or material having elastic qualities equal or similar to thin sheet-rubber, so stretched or laid and fixed on a frame skeleton bar that it is held in a smooth condition and somewhat in a state of tension, the frame or skeleton bar having a rectangular opening of suitable width to allow the hammers of the pianoforte-action to come in contact with one face of the diaphragm formed of such strip of material without touching the frame and the back or opposite face of the diaphragm having points or strikers fixed to it in position to lie next to the strings of the piano, so as to make contact with the strings when the front face of the diaphragm is struck by the hammer. These points or strikers correspond in number with the hammers of the action and are secured to the face of the diaphragm next to the strings. The frame or skeleton bar carrying the diaphragm is moved into and out of operating position between the hammers and the strings by mechanism connected with a pedal at the bottom of the case.

The following description explains at length the nature of the said improvement and the manner in which I proceed to construct and carry out the same,reference being had therein to the drawings that accompany and form part of this specification.

In the said drawings, Figure 1 is a front elevation of an upright piano with my improved attachment in place, the front of the case being removed and the action omitted to show the construction of the attachment more clearly. Fig. 2 is a front elevation of the attachment on an enlarged scale. Fig. 3 is a top view of Fig. 2. Fig. i is a front view, represented on a large scale, of a portion of the attachment at the left-hand side of the piano. Fig. 5 is a rear or back view of the right-hand end and a portion of the attachment. Fig. 6 is a vertical cross-section taken at a; 0:, Fig. 4, and illustrating the relative positions of the strings, the hammer, and the attachment when in operation.

A indicates the diaphragm or strip of elastic, B B the strikers fixedto its surface, and O the skeleton bar or frame by which the diaphragm is held in a smooth condition and under more or less tension. The frame has a rectangular slot or opening O through which the diaphragm or elastic material is lower ends to the outer ends of two levers E E, having fulcruins in the bottom of the case at F F, and connected at their inner ends with an operating-pedal G. When the pedal G is depressed, the bar 0 is drawn or moved down into position between the hammers and the strings, and when the pedal is released the bar 0 is thrown up out of the way of the hammers by springs H H, placed under the outer or longer members of the levers.

To the rods D are attached links or arms I), pivoted to the sides of the case at (1 the function of which parts is to keep the rods in upright position in their vertical movements.

The bar 0 may be constructed of wood or metal. In the one case the top and the bottom rails are made somewhat wider than if it be made of metal; but the bars of the metal frame are made of less thickness than when the frame is constructed of wood. Figs. 1 and illustrate the construction of wood,an d Figs. 4, 5, and 6 show a metal frame.

The slots 0 are cut in the bar from the bottom upward to let the attachment drop over the bolts that hold the action in place. The left -hand portion of the frame extending across the overstring bass is bent or formed with an offset, as seen in Fig. 3, to preserve the same relative distance or clearance between the bass-strings and the rear face of the attachment as at the remaining portion of the scale.

For the strikers B thin strips of ivory or hard-wood veneers are employed. They are fixed to the back or to that surface of the elastic diaphragm A which is next to the strings, and they are placed at such distances apart that each one will make separate and independent contact with the strings directly behind it. The strikers B, therefore, are placed in relatively close order to bring each one in line with its proper hammer and strings, but at the same time the movement of one striker under the impact of its hammer must not disturb the striker next adjacent to it on either side to a sufficient extent to move or bring them in contact with their strings, and each striker must touch and sound the strings behind it only under the stroke of its own hammer. This independent action is insured by cutting small holes or slits b fi in the diaphragm B between the strikers, as shown in Figs. 2 and 4, partially but not entirely separating the diaphragm on perpendicular lines between the strikers. This is done ordinarily at the lower notes of the scale and is emitted at the higher notes. This quality in the elastic diaphragm of stretching under the impact of the hammer is regulated also by the width or distance between the top and bottom rails of the bar 0 and the degree of tension under which the diaphragm is stretched over the opening between them. At the lefthand or bass side of the scale, therefore, the distance between the rails of the bar is as great as practicable, while at the opposite or treble side the size of the opening between the top and bottom rails of the bar is reduced. The width of the bar or frame is necessarily limited by the available room or space below the hammers of the action and between them and the dampers, as it will be understood that when the frame is lowered or moved into working position to bring the elastic diaphragm behind the hammers the bottom rail of the frame must occupy a position out of the path of the dampers.

In place of thin sheet-rubber any elastic tissue or fabric or material of similar elastic and vibratory qualities such, for instance, as parchmentcould be used for the diaphragm.

The attachment as thus constructed and applied for operation can be thrown into and out of working position either by the hand through the medium of a draw-stop, or, in a more convenient way, it is worked by the pedal G. (Shown in Fig. 1.) The frame 13 is attached to the ends of the rods D by slotted angular plates I and screws L L that allow adjustment of the frame both perpendicularly and horizontally.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is

l. Inapiano,in combination with the strings and the action of the piano, an elastic diaphragm interposed between the hammers of the action and the strings but normally out of contact with both and having strikers or contacts on the face next to the strings and in line with the striking-face of the hammers, the said diaphragm being confined at the top and bottom edges or longer sides.

2. In a piano, in combination with the strings and the action of the piano, a skeleton bar or frame having a rectangular opening, or openings, an elastic diaphragm fixed over said opening or openings, means for moving said frame into and out of working position bctween the hammers and the strings to receive the blows of the hammers on the front face of the diaphragm when in working position and to stand out of the path of the hammers when not in operation, and strikers or contacts on the opposite face of the diaphragm in line with the hammers, as specified.

3. The combination of the skeleton frame having an opening or openings extending the full length of the pianoforte-action to take in the hammers, an elastic diaphragm stretched across said opening and strikers or contacts on the back face of said diaphragm at intervals of distance apart, the diaphragm being perforated or partially separated between said strikers, as specified.

4. The combination with the skeleton frame having an opening or openings, an elastic diaphragm stretched across said opening or openings, strikers or contacts on the back face of said diaphragm at intervals of distance apart,

the said diaphragm being partially separated In testimony that I claim the foregoing I between the said strikers, and means for moving said frame into and out of Working position with respect to the strings and the ham- 5 mers of a piano, as described consisting of Witnesses:

have hereunto set my hand and seal.

JOHN 0. KING. [L. s]

O. N. M. SMITH, M. REGNER.

the rods D -D, levers E E, pedal G and springs H, substantially as specified. 

